Question 463481
{{{(a+b)^2=(a+b)(a+b)=a(a+b)+b(a+b)=a^2+a*b+a*b+b^2=a^2+2ab+b^2}}}, and 

{{{a^2+2ab+b^2}}}≠{{{a^2+b^2}}}.

  To clarify this fact plug a=2 and b=3:(2+3)^2≠2^2+3^2 or 25≠13.